i'm sure that it'll grow back. x: my Cup had his fins shredded by a plastic plant, and they all grew back together just fine. even his ventril, which was ripped in half, is starting to grow back. if you can get your hands on some Indian Almond Leaves, plop one in his tank. it's good for helping fins regrow and heal up.

No no dont euthanize. Maybe put him in a cup and do the aquarium salt treatment or just keep the water really clean, depending on his wounds, pictures are good.... Maybe ms fishy fish got tired of him checking her out and hopped out of the cup, beat him up, then hopped back in =x lol nah just kidding :)
Is their anything he could have gotten stuck between or scraped on? When my male seen my female he went crazy and started thrashing around onto everything trying to show off.

i didn't know there were so many kinds of oaks! xD i'd ask OFL before you go plopping random oak leaves in your tanks. i DO know they have to be naturally fallen, naturally dried, free of any kind of chemical.

I think i read That any oak tree is okay as long as they are naturally dried and free of chemicals. Its just that some types of oak leaves release the tannins faster then others. I just grab any oak leaves, break them up in a cup of water, let them soak a week then net out the leaves and add to my gallons XD